Netgear WNDR4500v3 - Bootloop after first reboot

I'm very new to router firmwares in general, so I'm stuck.

OpenWRT was the only firmware that supposedly supported the WNDR4500v3, so I decided to install it on my router. Apparently, only the snapshots (no stable releases) were available.

I'm in the same situation as described in this 6-month-old thread (WNDR4500v3 - Kernel Panic - not syncing: VFS ), but I have no idea what a UART port is, nor what it looks like.

What's a UART port? And how can I use it to flash the default firmware of my router?

I cannot find a board picture of v3 with serial connectors marked. Only v1. But better then nothing:

As it seems to me that you do not know anything about UART or Serial connections at all it might be a very tough task to get the router back to "life".

Some basics:

It might be that nmrpflash is working for your device. So you would not have to mess around with serial connection.

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It seems nmrpflash worked, good.
According to the original thread, the (current) procedures are to install the kernel, and then upgrade it via scp/sysupgrade (though I have to "Change the network.lan.ipaddr to avoid conflict...", whatever that means).
I'll update whether this works.

I've figured it out, after a few attempts.
Note that this may be fixed in the future, but until that happens, this is one way that works.

  1. Have the -factory.img and -sysupgrade.bin files downloaded.
  2. Flash the OpenWRT image as normal, but when it completes, DO NOT REBOOT THE ROUTER (or else you're gonna have to use nmrpflash and retry).
  3. Connect to your router via ssh: ssh root@
  4. Set a password: passwd
  5. Exit out of ssh: exit
  6. With your -sysupgrade.bin file, send it to the router's /tmp/ folder via scp:scp openwrt-ath79-nand-netgear_wndr4500-v3-squashfs-sysupgrade.bin root@
  7. Reconnect via ssh and upgrade the firmware via sysupgrade: sysupgrade -v /tmp/*.bin
  8. Your router will reboot and won't bootloop, for some reason; I didn't think the upgrade would change anything.
  9. Reset the router to get it out of the read-only mode via the reset button: Using a paperclip or earing, hold the reset button for 10 seconds and wait for the router to reboot.
  10. Reconnect via ssh and install the LuCI web interface, since it doesn't come with snapshot images: opkg update; opkg install luci
  11. You're done! Connect to the web interface with, and edit and enable your Wi-Fi networks.

Luckily, the image is getting more stable with each passing day.
(Just update the router whenever it bootloops or an actual stable release for the router comes. Just keep a copy of nmrpflash and the latest default firmware, which is currently labelled "WNDR4500v3-V1.0.0.60.img", on the ready.)

Yes, the board for NETGEAR WINDR4500v3 is close to the v1. But in my memory there are only the 4 standard pins (GND, Tx, Rx, +3V).

Thank you for the nmrpflash tool.

About "Change the network.lan.ipaddr to avoid conflict...", i have to change the ip because of error message (the router was unreachable).

Thank you NekoAlosama, I will try your method next time :slight_smile:

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